INDIANAPOLIS – Mallory Comerford kept talking about the supportive and stimulating environment at the University of Louisville. Surroundings in Indianapolis must favor her, too.

Put it this way: She is 2-1-1 in four swims over three meets and four months at the Natatorium at IUPUI. She beat one Olympic gold medalist from Stanford, Simone Manuel, and tied another, Katie Ledecky.

Comerford produced the opening night shocker of the Phillips 66 National Championships, beating Manuel in the 100-meter freestyle Tuesday.

Comerford’s time was 52.81 seconds, narrowly missing the American record of 52.70 set by Manuel in tying for gold at the Rio Olympics. Manuel was second in 53.05 to qualify for the U.S. team that will compete in the World Championships next month at Budapest, Hungary.

Comerford was 12th in the 100 freestyle at last year’s Olympic Trials. Now she could be on her way to world medals.

“A few years ago, I would have been like, ‘No way,’” said Comerford, 19, of Kalamazoo, Mich. “I’ve been at Louisville for three summers now, and a lot has changed. It’s been the greatest experience of my life.”

Comerford said she is still “trying to figure out” long course, the 50-meter pools that are more than twice as long as a 25-yard college pool. So shortly before the NCAA Championships, she came to Indianapolis and beat an international field to win the 100-meter freestyle in 53.91 in an Arena Pro Series meet.

At NCAAs, she finished third in the 100-yard freestyle behind Manuel, and tied Ledecky in the 200-yard freestyle.

“I just love to race,” Comerford said.

Manuel did not race poorly. Indeed, her time was faster than her 53.52 from the Olympic Trials. Now that she has made the team, she said, the pressure is off.

“I didn’t rest much for this,” Ledecky said. “Compared to other trials and selection meets, this might be the least tapered that I’ve been over the last couple of years.”

Jack Conger, who along with Haas led Texas to the NCAA team title, won the 200 butterfly in 1:54.47. Conger, who was third in this event at the Olympic Trials, was one of the swimmers caught up in the gas station incident with Ryan Lochte at Rio. Conger apologized afterward and was suspended for four months by USA Swimming.

Call IndyStar reporter David Woods at (317) 444-6195. Follow him on Twitter: @DavidWoods007